Enoshita Castle, Feudal castle ruins in Midori Ward, Japan.

Enoshita Castle consists of ruins from the Muromachi period with preserved defensive structures including elevated earthen walls and dual moats around a central compound. The layout reveals the typical organization of a Japanese castle designed for both military defense and administrative control.

Enoshita Castle was built in the Eikyō era (1429–1441) by Uesugi Norikiyo of the宅間上杉 branch. In the Eikyō War of 1438 his son Norinao held it for Ashikaga Mochiuji, then withdrew and took his own life at Shōmyō-ji. Under the later Hōjō it served as an outpost of Odawara's Koyama Castle, and around 1603 the Satō family founded Kyūjō-ji within its grounds.

The castle grounds became the site of Kyūjō-ji, founded around 1603 by Satō Kozaemon, who built a retirement residence within the former castle area. The temple's name preserves the memory of the fortification, and the grounds remain a place of worship today.

The site is accessible through maintained walking paths that offer clear views of the fortification structures. Plan time to explore the different levels and earthworks throughout the grounds to fully understand the layout.

The castle name survives as the Yokohama city bus stop "Enoshita Castle Ruins Rear". A stone monument to Yamada Ukyō-no-suke, placed in 1935 when the Yokohama Bōeki Shimbun named the site one of 45 scenic and historic places in the prefecture, is registered as No. 15 in Midori Ward's own heritage list.